阿奇霉素对香烟烟雾致肺泡Ⅱ型上皮细胞损伤的保护作用及其机制研究

Protection of azithromycin against pulmonary II epithelial cell injuries induced by cigarette smoke extract and relevant mechanisms

摘要:

目的：香烟烟雾提取物(CSE)可导致肺泡Ⅱ型上皮细胞损伤、核因子-κB(NF-κB)活化和肿瘤坏死因子(TNF-α)分泌增加,阿奇霉素对CSE诱导肺泡Ⅱ型上皮细胞(A549)中的这些损伤是否有保护作用目前尚不清楚，该实验对此进行研究并探讨其作用机制。方法：体外培养A549，分为空白对照组、阿奇霉素阴性对照组、CSE组和CSE+阿奇霉素组，在8 h后使用倒置显微镜、免疫组化染色(SP)和酶联免疫法（ELISA）观察检测上述条件下A549细胞的形态、NF-κB活化和分泌TNF-α水平的变化。结果：CSE可导致细胞形态和结构的改变，同时诱导产生染色呈深棕黄色颗粒的强阳性NF-κB细胞,其TNF-α分泌水平达0.307±0.036 pg/mL，而CSE＋阿奇霉素组细胞形态和结构有所恢复，NF-κB染色亦相对变浅, TNF-α水平较CSE组减少，为0.269±0.009 pg/mL，空白对照组、阿奇霉素阴性对照组无上述形态学变化，NF-κB染色为蓝紫色，TNF-α水平分别为0.234±0.028 pg/mL和0.259±0.014 pg/mL。结论：阿奇霉素可部分抑制CSE刺激的细胞NF-κB活化，减少TNF-α的分泌，减轻CSE对肺泡II型上皮细胞的毒性作用。［中国当代儿科杂志，2007，9（1）：63-66］

Abstract:

OBJECTIVE: Cigarette smoke extract (CSE) can induce injuries of pulmonary II epithelial cells, activate nuclear factor-κB and increase tumor necrosis factor-α(TNF-α) secretion. This study aimed to investigate whether azithromycin can protect pulmonary II epithelial cells from injuries induced by CSE and relevant mechanisms. METHODS: Pulmonary II epithelial cells (A549 cells) were cultured in vitro. After 48 hrs of culture the cells were randomly treated with serum-free DMEM only (blank control group), azithromycin + serum-free DMEM, CSE+ serum-free DMEM or CSE+azithromycin. Eight hours later the morphology of A549 cells, the activity of NF-κB and the levels of TNF-α were measured by inverted microscope, immunohistochemistry and ELISA. RESULTS: The morphology and structure of A549 cells were changed, NF-κB activity increased (dark brown staining ) and TNF-α levels (0.307±0.036 pg/mL vs 0.234±0.028 pg/mL)increased in the CSE+ serum-free DMEM group compared with the blank control group (P<0.01). CSE together with azithromycin treatment recovered partly the morphological injuries of A549 cells. It also attenuated NF-κB staining and decreased TNF-α levels from 0.307±0.036 pg/mL (CSE+serum-free DMEM group) to 0.269±0.009 pg/mL (P<0.05). CONCLUSIONS: Azithromycin may inhibit NF-κB activity, decrease TNF-α secretion and thus lessen cytotoxicity of CSE to A549 cells.［Chin J Contemp Pediatr, 2007, 9 (1) :63-66］